Regular coffee consumption reduces the risk of stroke in women, according to a new study. The study, published in Circulation: Journal of the American Heart Association, shows that women who drank four or more cups of coffee a day had a 20% reduced risk of stroke compared to women who had less than one cup per month. Drinking two to three cups per day reduced risk by 19%. Drinking a cup five to seven times a week reduced risk by 12%.

Researchers analyzed data on 83,076 women who participated in the Nurses' Health Study. Participants began the study in 1980 with no history of stroke, heart disease, diabetes, or cancer. Every two to four years, the women filled out food frequency questionnaires about their diets. During the study, which lasted 24 years, 2,280 strokes were documented.

The benefits of coffee are much more significant for nonsmokers. For women who had never smoked or quit the habit, drinking four cups or more of coffee a day was associated with a 43% reduction in stroke risk. For women who smoked, drinking four cups or more was associated with only a 3% reduction in risk.

“The potential benefits of coffee cannot counterbalance the detrimental effects smoking has on health,” Esther Lopez-Garcia, lead author of the study and assistant professor of preventive medicine at the Universidad Autonoma de Madrid, Spain, says in a news release.

The benefits do not appear to come from caffeine. Participants who drank tea and caffeinated soft drinks did not experience the same reduction in stroke risk. “This finding supports the hypothesis that components in coffee other than caffeine may be responsible for the potential beneficial effect of coffee on stroke risk,” Lopez-Garcia says. “Antioxidants in coffee lower inflammation and improve blood vessel function.

“The beneficial effects of coffee can only be applied to healthy people," she says. "Anyone with health problems that can be worsened by coffee (insomnia, anxiety, hypertension, or heart problems) should talk to their doctor about their specific risk.”

And the data suggest that women still need to pay attention to any stroke risk factors they may have. Drinking coffee will not make those risk factors go away.